Expanded Indication Thoracic Endovascular Aortic Repair: The Effect of Case Complexity on Outcome

BACKGROUND: Since FDA approval, operators have increased TEVAR indications from the original indications for use. However, data from multi-institutional studies are lacking with respect to contemporary outcomes following complex TEVAR. The aim of this study is to describe the effects of increasing anatomical complexity on outcomes following TEVAR.
METHODS: National Surgical Quality Improvement Program data were gathered prospectively for all patients undergoing TEVAR during the interval 2003 to 2008 at 211 centers. Concurrent procedures were identified to further stratify by surgical complexity, which included cases of left subclavian artery coverage and aortic debranching (complex) or cases isolated to the descending aorta (simple). Study end points included the 30-day occurrence of any stroke, death, paralysis or cardiac event. A variety of demographic, clinical and operative variables were assessed with multivariate models to identify risk factors associated with the composite (stroke, death, paralysis or cardiac event) end point and significance assigned with p<0.05.
RESULTS: A total of 440 cases were performed during the study period: 288 were identified as simple and 152 as complex (21 cases of arterial bypass, 131 cases of left subclavian artery coverage). Demographic and co-morbid profiles were similar between the two groups with the exception of dialysis (2.78% simple, 7.89% complex, p=0.0143). The composite (stroke, death, paralysis or cardiac event) rate was 12.5% in all cases, 9.72% in simple cases, and 17.76% in complex cases (p=0.0222). The multivariate analysis showed that case complexity was an independent predictor of a negative event. (OR=1.984, CI 1.104-3.568) There were no clinical or demographic variables associated with a negative event.
CONCLUSION: Anatomic complexity is the principle independent variable associated with major adverse events following TEVAR, not clinical or demographic factors. These data diverge from the original FDA-approval data, and provide practical endpoints for patients with complex thoraco-abdominal disease. There is an increased risk of adverse events in patients with complex anatomy, and patients must be counseled appropriately vis-à-vis these results, including non-operative and open repair.